If you decide you want to chase Marlin on the Goldy, Ross McCubbin on Lucky Strike would be my first call and also the boys on Mufasa Sport Fishing also seem to find their fair share of both black and blue Marlin. Another boat to look at would be Sparra's boat Hotshot, he does the season up in Cairns aswell as the Good Coast season also, but the two boats I mentioned earlier generally seem to find a few more marlin then my last recommendation. Probably for a first timer, chasing the smaller blacks would be a good starting point option for your wife, the bigger blues are a serious work out, even when you are running heavy gear and sitting in the chair. Generally speaking the smaller blacks will put on a better show jumping out of the water more often and are more lively when you get them to the boat (as it doesn't as long), many a time the bigger fish jump at the start and then dive deep, and you as the person on the end of the rod can miss that action whilst you are jumping in the chair and hooking the rod up. What ever you decide on it's great fun when you hook onto something, but it can be very boring trolling for hours and hours on end without a hit of the lines.